"There's a significant investment for a lot of people to make and at a time when their production is down and they're not quite sure when their grass is going to grow again, committing to spending a lot of money now is going to be a challenge to a lot of farmers."

On the cost, Mr Campbell gave as an example a farmer running a seminar at the expo, who has 800 cows and has just invested $230,000 on his storage pond, solids separator and associated ponds.

However, Mr Campbell says farmers who have plenty of effluent storage capacity are at an advantage during droughts.